This invention pertains to a disc roller mechanism and method used for forming helical shapes from a resilient wire or bar stock material using multiple rotatable disc-shaped forming rollers. It pertains particularly to such a disc roller forming mechanism and method in which the feed wire is continuously drawn through the multiple forming rollers while the wire is being simultaneously rotated about its own longitudinal axis, so as to form helical shapes having various desired parameters of diameter and pitch.
Mechanisms for forming of helical shapes have been previously developed, as disclosed by U.S. Pat. No. 2,749,962 to Kitselman and U.S. Pat. No. 2,769,479 to Schane. However, in both these wire forming mechanisms the wire being formed is pushed by a feeding means through rotating forming rollers, which can result in large compressive stresses being developed in the wire and can cause undesired deformation and buckling of the wire, particularly for small diameter wires which are relatively flexible and prone to bending. Such wire instability problems when forming helical shapes are substantially eliminated by the present invention, which advantageously draws the wire through the multiple forming rollers and utilizes small tensile forces developed in the wire being formed to provide a superior helical-shaped structural product.